How do you think pollutants are removed from the atmosphere? does this occur quickly or slowly?

A tree is able to remove air pollution via its leaves in two ways. The first is by direct uptake through the leaves in 2 ways ... The amount of pollution removal was calculated for ozone (O 3), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and particulate matter less than ten microns (PM10).

Maybe a couple days to a week.